Add stable /next and /featured URLs that redirect to the current event.

These short links always resolve to the latest upcoming or featured event so they can be shared without updating when events rotate.

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/src/lib/api/events.ts

@@ -11,6 +11,8 @@ export const eventsApi = {
 
   getById: (id: string) => fetchApi<{ event: Event }>(`/api/events/${id}`),
 
+  getNext: () => fetchApi<{ event: Event | null }>('/api/events/next'),
+
   getNextUpcoming: () => fetchApi<{ event: Event | null }>('/api/events/next/upcoming'),
 
   create: (data: Partial<Event>) =>